The family of Osama bin Laden's youngest wife have broken their silence to describe how the 29-year-old Yemeni, currently in the custody of security services in Pakistan, refused the chance to leave her husband, saying instead she was determined be "martyred" alongside him.

The relatives of Amal Ahmed al-Sadah, who became the al-Qaida leader's fifth wife in late 1999, spoke of a "sincere" husband – though one who apparently exaggerated tales of his own bravado for the sake of his in-laws.

Sadah, who Pakistani officials say was wounded in the calf during the operation that killed her husband, was among at least a dozen women and children detained by Pakistani security officials after the raid on the Abbottabad compound where Bin Laden had been living for several years. It is believed the American special forces team that carried out the operation was forced to abandon plans to evacuate survivors after losing of one of their four helicopters because of a technical problem.

Among those detained are two other women who have also been identified as wives of Bin Laden by Pakistani officials. However, this is unconfirmed. If true both would be Saudi nationals. The children appear to be a mixture of Bin Laden's own and his grandchildren. They include Sadah's daughter, Safiya, who was born shortly before the 9/11 attacks.

Pakistani officials have repeated that all those detained will be repatriated to their countries of origin.

Sadah's family spoke to a reporter from the Associated Press news agency in their two-storey traditional home in Ibb, an agricultural town in the mountains about 100 miles south of the Yemeni capital, Sana'a.

They said they saw Sadah, who was 17 when she was married, only once after her wedding, in 2000. Communication was largely limited to messages delivered by couriers.

The family said Sadah was a simple but determined and "courageous" young woman who was religiously conservative but not fundamentalist and who may have seen marriage with Bin Laden, a hero for some in the Islamic world and the son of a major construction magnate, as a means of social mobility.

Sadah, whose father is a minor civil servant, always told her friends and family that she wanted to "go down in history", according to her cousin Waleed Hashem Abdel-Fatah al-Sadah.

A cleric based in Kabul called Rasheed Mohammed Saeed, who had radical Islamist contacts, relayed the demand for marriage with Bin Laden. Sadah's uncle Hashem recalled telling her he knew Bin Laden was from a "devout and respectable family" in Saudi Arabia, though he was unaware that the militant leader "was wanted by the Americans" for the 1998 bombings of US embassies in Kenya and Tanzania.

"The choice is yours," the uncle said he told her. "It's your future."

The answer was unequivocal: "This is destiny from God, and I accept it."

Weeks after the proposal, a dowry of $5,000 was wired by Bin Laden.

After two wedding parties, including one in a Sana'a hotel, Sadah left Yemen. Accompanied by the intermediary, she travelled via Dubai and Pakistan to meet her bridegroom for the first time.

When the family learned through a courier that she had given birth to a daughter, a group of relatives travelled via Pakistan to Afghanistan, where they spent a month.

On the final day of the visit, a cousin recalled Bin Laden telling the young mother that she could stay with him in Afghanistan or return home with her family. "I want to be martyred with you and I won't leave as long as you're alive," he recalled her saying. When Bin Laden told her he was "subject at any moment to death", Sadah told him curtly: "I've made my decision."

The woman's cousin recalled her describing Bin Laden as a "noble" man who treated her well.

"'It's true that my life is one of moving between caves in Afghanistan, but despite the bitterness of this life ... I'm comfortable with Osama," she told her father.

Sadah's uncle said Bin Laden complained about Arab leaders and said he had been the focus of several "assassination" attempts by Arab and US intelligence services. The al-Qaida leader appears to have exaggerated his anecdotes for the benefit of his in-laws, telling them that a mosque in which he was delivering a sermon was struck by a cruise missile.

"I was injured ... and a lot of people were killed," Bin Laden reportedly said. "But I was spared from death because God wished it."

There is no other record of such an incident. When in August 1998 the US fired cruise missiles at four militant training camps in Afghanistan in retaliation for the bombings of American embassies in east Africa, Bin Laden was many miles away.

The cousin said Bin Laden told the family during their visit to Afghanistan "of a big event that will occur in the world".

Later, when the cousin and Sadah's father heard the news of the 9/11 attacks, the father had now doubt who was behind them.

"Osama bin Laden did it," he said.

For the moment, the future of Sadah and the other women in Pakistani custody is unclear.

American intelligence services are keen to interview those detained in the raid in the belief that they could provide crucial intelligence about the workings of al-Qaida, the recent activities of Bin Laden and his personal life, and whether they had received support from Pakistani authorities.

"It is fairly unlikely that Bin Laden would be sharing operational details with his wives. That isn't his way or his culture. But there are other things they should know about, such as the whereabouts of other relatives," one recently retired US intelligence official told the Guardian.

One key topic, the former official said, would be the exact conditions of the large numbers of Bin Laden's close family who have been detained in Iran since they fled Afghanistan in the wake of the 9/11 attacks and the fall of the Taliban regime.

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